As compared with traditional cathode ray tube display devices, flat panel display devices have advantages such as lightness, thinness, low driving voltage, no flicker, no jitter, long service life, etc. Flat panel display devices can be classified into active luminous display devices and passive luminous display devices. For example, thin film transistor liquid crystal display devices (TFT-LCD) belong to a kind of passive luminous display devices. As TFT-LCDs have the merits of stable picture, lifelike image, small radiation, saving in space, saving in energy consumption, and so on, they have been widely applied to televisions, cell phones, display devices and other electronic products, and have played a leading role in the field of planar display.
A liquid crystal display device mainly includes a liquid crystal display panel and a drive device for driving the liquid crystal display panel. The liquid crystal display panel mainly includes a first substrate and a second substrate that are disposed opposite to each other; usually, the first substrate and the second substrate are an array substrate and a color filter substrate, respectively. The array substrate includes a plurality of data lines and a plurality of gate lines that intersect with each other, and a plurality of pixel units are defined by the data lines and the gate lines.
Manufacturing processes of the liquid crystal display panel are mainly classified into a front-end array process, a middle-end cell process, a back-end module assembly process and so on. In order to reduce the difficulty in testing pictures of the liquid crystal display panel in the array process and the cell process and reduce the cost of testing equipment, one of the most commonly used method in the industry at present is to arrange a shorting bar region on the array substrate. That is, some wirings for test are formed to surround data lines, gate lines and other wirings on the array substrate.
As shown in FIG. 1, a first test line 3 and a second test line 4 are formed along the periphery of an array substrate. The first test line 3 is configured for signal test on data lines in all the odd-numbered columns, and the second test line 4 is configured for signal test on data lines in all the even-numbered columns. In order to measure the resistance between two adjacent data lines, two probes of a universal meter for example contact the two adjacent data lines, respectively, and whether a short circuit occurs between these two data lines or not can be determined in accordance with the obtained resistance value. For example, if the tested resistance value is very large, then it indicates that no short circuit occurs; while the tested resistance value is very small, then it can be basically determined that a short circuit occurs.
Because the shorting bar region is arranged along the periphery of the liquid crystal display panel, and for the convenience of test, the connection to a large number of data lines or gate lines in the liquid crystal display panel is required, accumulation of electrostatic charges occurs quite easily. For example, as shown in FIG. 2, static electricity may bring about an electrostatic breakdown in the region where metal lines overlap, leading to short circuit, open circuit or other defects. Moreover, because some shorting bar regions are situated at the edge of the array substrate, many process treatments are very unstable at the edge. For example, when an aluminum-containing material is used as the substance for a test line, due to a hillock or other issue existing at the edge, electrostatic breakdown happens more easily, so that a defect happens to a shorting bar region. A defect in a shorting bar region may make the whole liquid crystal display panel determined to be a defective product in test. However, the shorting bar region is cut off during the final phase of the production, and will not affect the display effect of the final display device. So, this gives rise to misjudgement. That is, it is possible that a part of products, in which liquid crystal display panels comply with specifications but a defect is present in a shorting bar region, are misjudged as disqualified products. Therefore, the yield of display devices is affected, and on the other hand, serious waste is incurred.